Time of Day Matters When it Comes to Cancer Diagnosis and Treatment

Our circadian rhythms help our bodies synchronize different tasks throughout the day, including gene expression, immune function, and cell repair. We’ve long known that chronically disrupted circadian rhythms can predispose us to a number of health issues.

Recent work has shown that circadian rhythms are not only involved in tumor onset, but also govern cancer progression and metastasis. 

For metastasis to occur, cells need to break away from the primary tumor, enter the bloodstream, and then travel to and infiltrate a new organ. Studies have shown that the rate at which cancer cells break away from the primary tumor and enter into the bloodstream oscillates rhythmically throughout the day, but the timing of this rhythm differs between cancer types.

“Circadian rhythm-based metastasis formation should be seen as an opportunity to intervene in the most timely and effective way,” the authors write.

The practice of delivering medication and immune therapies at specific times of day is known as chronotherapy.

Clinical studies have shown that chronotherapy can reduce the severity of side effects experienced by patients and can also impact treatment effectiveness. Knowledge of the circadian rhythms of cancer cells could also aid cancer diagnosis. Cancer cells produce proteins at different rates throughout the day, and some of these proteins are used as diagnostic molecular markers. 

“Defining the circadian-rhythm-controlled timing of proliferation and release of circulating tumor cells into the bloodstream in additional cancer types may help to identify the optimal time window for therapy administration” writes the author.


Zoi Diamantopoulou, Ana Gvozdenovic, Nicola Aceto. A new time dimension in the fight against metastasis. Trends in Cell Biology, 2023; DOI: 10.1016/j.tcb.2023.02.002

Cell Press. “Time of day matters when it comes to cancer diagnosis and treatment.” ScienceDaily. ScienceDaily, 24 March 2023. <www.sciencedaily.com/releases/2023/03/230324135223.htm>.

Images from:

Photo by Lukas Blazek